The present invention generally relates to a sealed, air-evacuated, article-containing package, and more particularly, concerns such a package with a visual indicator for determining the integrity of the package to assure a vacuum condition.
Many sterile, clean or perishable articles are packaged in air-evacuated containers in order to preserve those characteristics just mentioned. In sealing such air-evacuated packages, there is always the possibility that a defect in the package will occur by which the vacuum condition inside the package will be lost. For example, package material or seal failure could occur which would cause the vacuum inside the package to be lost since the pressures both inside and outside the package would tend to equalize.
In many such packages, there is no easy way to tell, especially by visual checking, whether the desired vacuum condition inside the package is being maintained. Various types of somewhat cumbersome testing techniques are often employed with these packages to make such a determination. For instance, one such testing method requires the introduction of a pressurized gas into a randomly sampled package which is partially submerged in a sterile fluid. Another method relies only on the visual appearance of sampled packages, and an arbitrary decision is generally made as to whether or not a suitable vacuum is being maintained inside the package. It can be seen that this type of testing is clearly arbitrary and subjective, with reliability and accuracy notably lacking in these procedures.
With such deficiencies such as described above facing those who attempt to easily and readily determine whether vacuum conditions exist inside an air-evacuated package, it becomes apparent that there is a need for improvements in technique. It is to the solution of these deficiencies that the present invention is directed.